The 2'-5' linked RNA is an RNA analog with the 2'-hydroxyl group of one ribonucleotide linked to a 5'-hydroxyl group of another through an internucleotide phosphodiester bond. The ability of 2'-5' linked RNA to form an orderly structure is largely unexplored. We have crystallized an RNA molecule with partially modified backbone by 2'-5' linkages. The crystals diffract to a resolution of 2.78 E with conventional x-ray source. Synchrotron radiation could greatly help the determination of the structure by collecting anomolous diffraction data at the absorption edge of bromine which was introduced to the 3'-end position.